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Docs/Deployment

Deploying Geno Browser Applications

Overview

Geno browser apps use the init/update/render lifecycle and compile to JavaScript + HTML for deployment to any static host.

Build

geno build Main.geno

Creates a dist/ directory containing:

  • index.html — entry page referencing app.js
  • app.js — compiled application code

Custom output directory

geno build Main.geno -o build/

Single-file output

geno build Main.geno --single-file

Creates a self-contained HTML file with JavaScript inlined.

Dev Server

For local development with live-reload:

geno dev Main.geno

Opens at http://localhost:3000. The page auto-reloads on file changes.

Options:

geno dev Main.geno --port 3000 --width 1024 --height 768 --title "My App"

Deployment Targets

GitHub Pages

name: Deploy
on:
  push:
    branches: [main]
jobs:
  deploy:
    runs-on: ubuntu-latest
    permissions:
      pages: write
      id-token: write
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.11"
      - run: pip install geno-lang
      - run: geno build Main.geno -o dist/
      - uses: actions/upload-pages-artifact@v3
        with:
          path: dist/
      - uses: actions/deploy-pages@v4

Netlify

geno build Main.geno -o dist/
netlify deploy --prod --dir=dist

Or set up automatic deploys with a netlify.toml:

[build]
  command = "pip install geno-lang && geno build Main.geno -o dist/"
  publish = "dist/"

Vercel

geno build Main.geno -o dist/
vercel --prod dist/

S3 / CloudFront

geno build Main.geno -o dist/
aws s3 sync dist/ s3://my-bucket/ --delete

Any static host

The dist/ directory contains only static files. Upload it to any web server or CDN that serves HTML/JS.

Migrating from --single-file

Earlier versions of Geno produced a single HTML file by default. The current default is dist/ directory output, which is preferred because:

  • Separate app.js enables browser caching and CDN delivery
  • Optional source maps (app.js.map) enable debugging in DevTools
  • Faster incremental rebuilds (only changed assets are regenerated)

If your CI or deployment scripts assume a single file, update them:

-geno build Main.geno -o app.html
+geno build Main.geno -o dist/

Use --single-file only when you need a truly self-contained artifact (e.g., embedding in an iframe, email attachment, or offline distribution).

Source Maps

Source maps (app.js.map) are generated only when requested. They map the compiled JavaScript back to original .geno source files, enabling debugging in browser DevTools.

geno build Main.geno -o dist/ --source-map

Keep source maps out of production builds unless you intentionally want to publish the original Geno source for debugging.

Rendered from docs/deploy/browser.md in the Geno repository.